1. Field of the Invention
The present invention relates to a method for producing a friction plate adapted for use in an automatic transmission or a lock-up clutch of vehicles such as automobiles and an apparatus therefor.
2. Related Background Art
In the prior art, plural segments of friction material are adhered to a core plate with a predetermined gap between the segments, thereby forming oil grooves for lubricating oil on the friction plate.
FIG. 8 shows an example of such conventional method for producing a friction plate. Segments of the friction material are prepared for example by punching from a tape 5 of the friction material. The segments 3 of the friction material are fixed on a core plate 1 with gaps 4 in the circumferential direction to form a friction plate 10, and such gaps 4 constitute oil grooves.
The above-described conventional method for forming the friction plate has been associated with the following drawbacks:
1) As the plural segments of the friction material are extracted from the friction material tape and are adhered with predetermined gaps to the core plate, there are required time and work for forming the oil grooves of the required number; and
2) Also as it is necessary to obtain the friction material segments of a relatively large number from the tape, the throughput of the material such as the tape of the friction material is undesirably low, resulting in a significant waste of the material.
In consideration of the foregoing, an object of the present invention is to provide a method for producing the friction plate capable of improving the throughput of the friction material and reducing the time required for adhering the segments of the friction material to the core plate.
For attaining the above-mentioned object, the present invention is firstly featured by a method for producing a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments:
wherein the oil grooves are formed by plastic working of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is secondly featured by a method for producing a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments:
wherein the oil grooves are formed by cutting of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is thirdly featured by an apparatus for producing a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments, comprising:
means for punching a band-shaped friction material to obtain plural friction material segments;
means for holding the friction material segments by stacking on a metal mold or a jig and pushing out the friction material segments in succession to a side opposite to the metal mold; and
means for pressing and adhering the friction material segments to the core plate;
wherein the oil grooves are formed by plastic working of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is fourthly featured by an apparatus for producing a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments, comprising:
means for punching a band-shaped friction material to obtain plural friction material segments;
means for holding the friction material segments by stacking on a metal mold or a jig and pushing out the friction material segments in succession to a side opposite to the metal mold; and
means for pressing and adhering the friction material segments to the core plate;
wherein the oil grooves are formed by cutting of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is fifthly featured by a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments:
wherein the oil grooves are formed by plastic working of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is sixthly featured by a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments:
wherein the oil grooves are formed by cutting of the friction material and fixation of the friction material segments with a predetermined gap therebetween to the core plate.
Also the present invention is seventhly featured by a friction plate formed by fixing friction material segments, formed from a friction material, to a core plate and having oil grooves communicating between the internal periphery and the external periphery of the segments:
wherein the friction material segments are fixed with a predetermined gap therebetween to the core plate and then subjected to cutting for forming the oil grooves.
The time required for adhering work can be reduced since the friction material segments of a number fewer than in the prior art are adhered to the core plate. Also the throughput of the material can be improved.